Inhibition of Tilletia laevis Teliospore Germination and Suppression of Common Bunt of Wheat by Pseudomonas fluorescens 2-79. P. S. McManus, Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824-1312. A. V. Ravenscroft, and D. W. Fulbright. Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824-1312. Plant Dis. 77:1012-1015. Accepted for publication 21 June 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-1012.

A rifampicin-resistant derivative of Pseudomonas fluorescens strain 2-79 (Pf2-79r) inhibited teliospore germination of Tilletia laevis. A rifampicin-resistant derivative of a spontaneous mutant of strain 2-79 deficient in phenazine-1-carboxylic acid production (2-79PCA¯r) had no effect on germination of T. laevis. Inhibition of germination by Pf2-79r was not overcome by supplementing culture media with iron. Common bunt incidence was reduced by 65 and 50% during consecutive seasons when wheat seeds and 2-wk-old seedlings were treated with Pf2-79r. Similar treatment of seeds and seedlings with 2-79PCA¯r afforded no protection against common bunt.

Keyword(s): biological control, smut, Tilletia caries, Tilletia foetida, Tilletia tritici, Triticum aestivum.